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Rangga Prastio
ID

I build the hard parts.

Senior frontend and mobile engineer with 7+ years of shipping Angular, React, and React Native for teams in Europe, the US, and APAC. Backend roots and an AI-powered workflow mean you get the whole feature, shipped faster.

Taking freelance and contract work, 20–40 hours a week.

The Hikode mark drawn as a bridge from idea to productionIdeaProduction7+ years in production15°within tolerance
Move through it. Click to break it.
years shipping
7+
teams led
3
client regions
EU, US, APAC
working time zone
UTC+7

Selected work

Products in real users’ hands: a housing estate system built solo, a rental app with 500K+ downloads, a revenue platform, and offline tools for building engineers.

hiwarga.id
Hi Warga landing page with an estate map showing which houses have paid this month

Hi Warga

Housing estate system for IPL billing, the cash book, residents, and field officers. A company product I designed and built end to end, alone.

Stack
Laravel, Inertia, React, TypeScript, React Native, PostgreSQL, Docker

Read the case study

No signalSyncs when onlineNo signalSaved on device

Be Management

Building management platform for apartments. I led the frontend, then the project, and built offline checks for engineers on rooftops and basements.

Stack
Angular, NgRx, Offline-first, Node.js, Express, MongoDB

Read the case study

hubbly.io
Hubbly.io landing page: drop your website in and Hubbly does your marketing and sales

Hubbly.io

Autonomous revenue platform for SMB and mid-market teams. I joined as senior frontend and grew into project lead, working with shareholders.

Stack
Next.js, TailwindCSS, Zustand, WebSocket

Read the case study

Switching between a personal and a business account in TRACtoGo
TRACtoGo home screen with car rental, airport transfer, bus rental, and TRAC Attraction

TRACtoGo

Car and bus rental app by TRAC (Astra), 500K+ downloads. I built its B2B2C features alone and shipped them to iOS and Android.

Stack
React Native, TypeScript, Redux, iOS, Android

Read the case study

All projects

A career, built span by span

Each pillar is a role. Its height is scope: from intern to leading three teams.

A career, built span by spanMay 2019Oct 2019Dec 2019Jun 2020Oct 2020Mar 2023Nov 2023Nov 2024Jul 2026
  1. Jul 2026 – Present

    4 mo, Full-time

    Senior Frontend DeveloperNow

    CheckProof, Sweden · Hybrid

  2. Nov 2024 – Jun 2026

    1 yr 8 mo, Full-time

    Lead Engineer

    Be Management, South Tangerang · Hybrid

  3. Nov 2023 – Jan 2025

    1 yr 3 mo, Full-time

    Senior Frontend Developer

    Nikel, Central Jakarta · On-site

  4. Mar 2023 – Jan 2024

    11 mo, Contract

    Mobile Application Developer

    PT Serasi Autoraya · via Esha Parama Technology, North Jakarta · Hybrid

  5. Oct 2020 – Nov 2022

    2 yr 2 mo, Contract

    Senior Frontend Developer

    PT Maju Gemilang Indotech, South Tangerang

  6. Jun 2020 – Aug 2020

    3 mo, Contract

    Frontend Engineer

    Telunjuk.com, Indonesia · Remote

  7. Dec 2019 – Jun 2020

    7 mo, Full-time

    Frontend Developer

    SALT · PT Ako Media Asia, Indonesia · Hybrid

  8. Oct 2019 – Dec 2019

    3 mo, Internship

    Full-stack Developer

    Dumbways Indonesia, Bintaro

  9. May 2019 – Aug 2019

    4 mo, Full-time

    Android Developer

    Glovory Technologies Indonesia, Indonesia

Work experience

Specification

What I build with, and how deep it goes.

  • Expert
  • Advanced
  • Familiar

Frontend

  • Angular
  • React
  • TypeScript
  • JavaScript
  • Next.js
  • Astro
  • NgRx / Redux / Zustand
  • Web Performance

Mobile & Backend

  • React Native
  • Node.js
  • Express & MongoDB
  • REST API Design
  • Laravel / PHP
  • Inertia.js
  • PostgreSQL

Styling & UI

  • TailwindCSS
  • Design Systems
  • Responsive Design
  • Accessibility
  • Motion & Interaction

AI-Assisted Development

  • AI-Assisted Dev (Kiro, Cursor, Copilot)
  • Agentic Workflows & MCP
  • Prompt Engineering
  • LLM API Integration

Testing & Quality

  • Vitest
  • Playwright
  • Test-Driven Dev

Tools & Platform

  • Git & CI/CD
  • Docker
  • Cloudflare / Vercel

Method: AI with engineering discipline

AI does not replace engineering. It multiplies it. Every AI output gets my review, my tests, and my name on it.

Safe

No credentials in prompts. Every AI-generated line is reviewed, type-checked, and tested before merge.

Directed

Small, well-scoped tasks, the model chosen per complexity, context prepared through docs and tests.

Measured

Agents handle research, scaffolding, and regressions; I stay on architecture and product decisions.

Field notes

Writing on frontend, mobile, and engineering decisions.

All notes

Got a hard part? Send it over.

Freelance and contract work, 20–40 hours a week. I usually reply within 24 hours.

Email me

ranggaprastio123@gmail.com

Shared working hours

Your time
--:--
Rangga’s time
19:58
UTC+7